Muffler for rotary gas engines



June 18, 1929. c. P. BROCKWAY MUFFLER FOR ROTARY GAS ENGINES Filed May21. 1919 3 Sheets-Sheet l l INVENTOR. v t I Car-lRBrockWay ATTORNEY June18, 1929. c. P. BROCKWAY 1,71 01 MUFFLER FOR ROTARY GAS ENGINES FiledMay 21. 1919 5 sheets-sheet 2 [II Ilm 16 I 17 1a 15 I INVENTOR. CarlPBroclrm ay ATTORNEY June 18, 1929.

c. P. BROCKWAY MUFFLER FOR ROTARY GAS ENGINES 'Filed y 21. 1919 3Sheets-Sheet ,lllll lll llllllll fi INVENTOR. far! 1? Brockwa BY I m I II I fllvllllll/l ATTORNEY Patented June 18, 1929.

UNITED: STATES 3,718,201 PATENT: OFFICE.

CARL P. BROCKWAY, OF TOLEDO, OHIO, ASSIGNOR TO INDUSTRIAL RESEARCH COR-PORATION, 0F TOLEDO, OHIO, A CORPORATION OF DELAWARE.

MUFFLER FOR ROTARY GAS ENGINES.

Application filed May 21,

This invention relates to improvements in mufflers for internalcombustion engines of the rotary cylinder type.

The principal object of the invention is the provision of means forreducing the noise of the engine exhaust by causing it to discharge intoa partial vacuum, formed by the movement of a nozzle or nozzles carriedby the rotating portions of the engine, the discharge of the spent gasesbeing from the rear of said nozzle or nozzles.

Another object of theinvention is the shaping of the nozzles and theirarrangement with respect to each other in such. manner that no nozzleshall interfere. with the functioning of any other nozzle.

A further object is the provision of a muffler so shaped and positionedas to present little resistance to rotation of the engine.

Other objects, and objects relating to details of construction andeconomies of manufacture, will appear as I proceed with the descriptionof that embodiment of the inven tion, which for the purposes of thepresent application, I have illustrated in the accompanying drawings, inwhich, I

Figure I is a side elevational view of a double, opposed cylinder,rotary'engine, embodying my invention, parts being broken away and otherparts shown in section in order to more clearly illustrate theconstruction. r

Fig. II is a cross-sectional view, taken on the line II-II, Fig. I.

Fig. III is a fragmental view partly cross-section on the line IIIIII,Fig. I.

Fig. IV is a cross-section of one of the exhaust nozzles, the sectionbeing taken upon the line IVIV, Fig. I.

Fig. V is a side elevational view of a rotary engine embodying adifferent modification of the invention, one of the inufliers beingshown in cross-section.

/ Fig. VI is an outside elevation of a fragment of the muffler, the viewbeing taken at right angles to that of Fig. V.

Fig. VII is a fragmental view partly in cross-section on the lineVII-VII, Fig. V.

Fig. VIII is a fragmental cross-section taken on the line VIIIVIII, Fig.V.

Similar reference characters refer to like parts throughout the views.

In the drawings, the invention is shown applied to a rotary enginehaving double, op-

posed cylinders 10, identical in construction,

1919. Serial No. 298,742.

vided with a pair of opposed exhaust ports 15,

extending through the cylinder walls in a direction parallel to theengine shaft 12. A yoke-shaped tubular mufiier has its ends bolted tothe cylinder so as to bring the extremities of its gas passage 16 intoregister with the exhaust ports 15. The mufiler extends outwardly fromthe cylinder in the rearward direction, that is, from the side which isbehind as the engine rotates. of the muiller chamber is of much largercrossse'ction than the exhaust ports 15, in order .to permit the gasesto expand considerably before leaving the mufller. That part of the wallof this transverse chamber which is farthest from the engine shaft, orin other words, radially outermost; is thickened and is provided with aseries of screw threaded openings to receive the correspondinglythreaded shanks of exhaust nozzles 17.

The nozzles 17 are flattened on their sides in such manner as to producea stream-line contour, shown in Fig. IV, in which the direction ofrotation of the nozzle is indicated by the arrow A. In the rear side ofeach nozzle is an exhaust discharge opening 18, shown in the drawing asa slot, extending substantially throughout the entire length of thenozzle. In revolving rapidly the nozzle 17 parts the. air. Due to therapidity of the motion the separated walls of air do not come togetheragain directly behind the nozzle, and consequently there is always asmall space just behind the slot 18 in which a partial vacuum exists. Itis into this vacuum that the gases are discharged, instead of against amore or less unyielding wall of air as in the case of the usual muflier.The discharged gases tend to hold apart the converging walls of air andto push in between them where they have nearly met. Hence there is noimpact of the The transverse portion gases against adense wall of air,and therefore l1ttle noise occurs.

In the modification of Figs. V to VIII inclusive, each engine cylinderhas two opposed 5 exhaust ports, but they are engaged at right angles tothe engine shaft instead of parallel to it, as in the firstmodification. The muffler 20 is roughly crescent-shaped and is attachedat its respective ends to both cylinders on the same side of the engine.On its lateral and outer sides are cooling flanges 21 and 22-respectively. A baflie plate 23 with a central opening 24 divides theinterior of the chamber into'two parts. Along the outer side of themufiler, I arrange a series of nozzles 25, which are preferably shapedlike saw teeth. The hollow interiors of the nozzles communicate with'theinterior of the muffler, and the nozzles are provided with dischargeopenings, preferably slots,

along their rear edges. Space must be left behind each nozzle for thevacuum which is formed as the nozzle rotates, and in order to accomplishthis result I prefer to make 25 the forward edges of the nozzlesinclined as shown in the drawing; Although in the drawing the mufiler isshown connected with two exhaust ports, one in each cylinder, andbecause of its crescent shape it is peculiarly adapted for this purpose,obviously it could be employed, if desired, to receive the exhaust froma single cylinder only, the attachment of the other cylinder beingmerely for the purpose of stabilizing the structure.

The two modifications'of my invention above described operate in thesame manner.

' The gas is first given an opportunity to expand in the largeinterior'of the muflier chamber, after which it is discharged throughslots at the rear edges of the nozzles, 40

move through it, each nozzle leaving a partial vacuum for a space in itsrear, behind which the walls of air gradually converge. Into this spacethe gas discharges and wedges in between the two walls of air, beinggradually absorbed by the air on each side as it moves along. In thisway, heavy impact of the gas against a'dense wall of air is avoided anda more or less gradual admixture of thetwo is brought about.Consequently the noise of the exhaust is greatly reduced.

Iclaim as my invention:

1. A mufiier adapted to be attached to a rotatable engine member, saidmuflier havlng an elongated portion with walls exposed to the air as-theenglne revolves and an ex.-

haust nozzle mounted in said mufller, said nozzle being adapted to partthe air and leave a partial vacuum in its rear, and having a gas exit atthe rear whereby the gas enters said partial vacuum.

2. A muffler for gases escaping from movable chambers comprising aflattened tube having front and rear edges, the front edge being broaderthan the rear edge, and the 7 rear edge having a slot formed therein.

In testimony whereof I afiix my signature.

CARL P. BROCKWAY.

